Electrochemical corrosion of silicon-infiltrated silicon carbide ceramics in aqueous solutions

Influence of Electrochemical Potentials on the Tribological Behavior of Silicon Carbide and Diamond-Coated Silicon Carbide

“…Herrmann et al [14] showed that domains of low electric conductivity show less chemical attack. As previous experiments have shown [16], in the SiSiC material the most intensive electrochemical corrosion takes place at the rims of the SiC grains. Si and the core of the SiC grains are less attacked.…”

“…On the other hand, the structure of the SiO 2 layer on Si and SiC seems to be different. On the Si very thin passivating layers (up to 5 nm) were found, whereas on the SiC the thickness of the electrochemical formed SiO 2 layers can reach up to 100 nm under the same conditions [14,16]. The consequence is that in the SiSiC material only a small fraction of the surface is affected by the electrical potential.…”

“…Knowledge of the electrochemical and tribochemical mechanisms is the key to improve the operational safety, availability, and durability of ceramic components in many applications such as pumps in the chemical industry or power plants. Recently, a detailed investigation of the electrochemical corrosion of different SiC materials were carried out using potentiodynamic polarization measurements in acidic and alkaline environments [12][13][14][15][16]. They observed the formation of a thin layer of SiO 2 on the surface in acid (HCl, HNO 3 ) and a more pronounced active corrosion in NaOH.…”

“…Beside this overall dependence, also deviation of the electrochemical reaction between different grains and even inside individual grains was found. In liquid phase-sintered materials (LPS SiC) and in silicon infiltrated materials (SiSiC), a core rime structure of the grains was observed with more pronounced corrosion at the rims [13,16,17]. This behavior is caused by the different doping levels of the core and rim resulting in different specific electric resistances and electrochemical corrosion.…”

Anodic dissolution of solid‐state sintered silicon carbide at high current densities

“…The authors exemplarily use the commercially produced EKasic D ® in this work. Based on earlier studies of the electrochemical corrosion behavior of EKasic D ® in alkaline solution the range of investigations is extended to current densities, which are relevant for ECM. Current densities typically for ECM range between 10 and 30 A/cm 2 .…”